The present invention relates to the treatment of crops especially, but not exclusively, the conditioning of grasses, and provides an improved crop-treatment apparatus and method.
Forage crops such as grasses which are surplus to immediate requirements are usually cut and field dried to provide animal fodder, particularly hay or silage, for the feeding of animals when fresh forage crops are not available. In temperate, especially maritime climates, the crops are at risk between cutting and harvesting (i.e. the field exposure time) because the adverse effects of light and rain and micro-organism activity can produce appreciable nutrient and dry matter losses. Accordingly, it is important to minimize the field exposure time to reduce the risk of such losses. However, the crops cannot be harvested until they have dried to a sufficiently high dry matter content for safe storage as animal fodder. In the case of hay, a dry matter content of about 80% is usually required.
The speed at which surface and sap moisture evaporate from the cut crop during field exposure depends inter alia on the physical condition of the crop. The principal barrier to moisture loss is the cuticle and the layer of epicuticular wax on the crop surface, and it is now common practice in agriculture to mechanically treat the crop in order to damage this barrier. Such mechanical treatment, which may take the form of crushing, lacerating, bruising, splitting, bending or scuffing the stem and leaves of the crop, is known as "conditioning". A variety of conditioning devices have been used or proposed (e.g. as in UK Patents Nos. 588,439 (Chilton), 662,303 (Goodall), 1,368,682 (Bucher Guyer) and 1,322,165 (NRDC) but none are entirely satisfactory. In particular, known conditioning devices often cause undesirable damage to the crop, resulting in high dry matter losses; are unsatisfactory (by reason of their complexity, weight and/or cost) for use with crop cutters (i.e. mowing machines) of greater than 3.5 m width; and usually have metal components which are liable to break during use and damage forage harvesters collecting the field dried crop.
Desirably a crop conditioning device should satisfy the following criteria:
1. Minimize fragmentation of the crop; PA1 2. Compensate for changing crop density; PA1 3. Limit physical damage to the cuticular barrier to leave the structural strength and resistance to leaching substantially intact; PA1 4. Allow adjustment for conditioning of different crops and for different treatment requirements; PA1 5. Minimize susceptibility to damage by extraneous objects, particularly stones, and to blockage by the crop; PA1 6. Uniformly treat the crop; and PA1 7. Provide a loosely structured swath or windrow having good resistance to settling.
In addition, the device should be relatively inexpensive to manufacture and maintain and readily adaptable to mowing machines of any width.